Gas-measuring systems with a mobile gas-measuring device are used in various applications for detecting various harmful gases. For example, mobile gas-measuring devices are necessary for detecting toxic gases for checking safety in industrial chemical processing plants or in fighting fires for the fire service. The mobile gas-measuring device is, in general, in functional connection with a base station. The base station is used to supply the mobile gas-measuring device with electric current and, in addition, for data exchange between the mobile gas-measuring device and the base station. The mobile gas-measuring device is operated either with a non-rechargeable battery or a rechargeable battery.
The battery makes available the electric energy for supplying and operating the mobile gas-measuring device. For charging the batteries of the mobile gas-measuring device, the mobile gas-measuring device has a plug-type connection with corresponding contacts. Furthermore, the base station is provided with corresponding opposite contacts or with an opposite plug-type connection. To charge the mobile gas-measuring device, the mobile gas-measuring device must be placed on a base station and the plug-type connection of the mobile gas-measuring device must be brought into mechanical and electric connection with the opposite plug-type connection of the base station. The mobile gas-measuring device and the base station are used, in general, as a gas-measuring system in a rough environment. As a result, high requirements are imposed on dustproofness and waterproofness as well as the robustness of the plug-type connection and opposite plug-type connection at the mobile gas-measuring device and the base station. Besides, gas-measuring systems are used in areas in which explosive gases may occur. As a result, increased efforts are needed for this plug-type connection and opposite plug-type connection to make it possible to avoid sparking when the contact is made or the contact is abolished between the plug-type connection and the opposite plug-type connection. The plug-type connections and opposite plug-type connections known so far are not, in general, mechanically robust and resistant and, furthermore, they can be cleaned with difficulty only. In addition, corrosion may hinder the transmission of energy from the base station to the mobile gas-measuring device.
DE 10 2005 045 272 A1 shows a gas-measuring system with a mobile measuring device, which comprises sensors for detecting gas concentrations and a first control and computing unit for processing the measured signals delivered from the sensors and means for data transmission. A base station has a bracket for mounting the measuring device, with a power supply unit, with a second control and computing unit for actuating alarm generators arranged in the base station and interfaces for feeding media to be measured to the sensors and for data exchange between the mobile measuring device and the base station. The base station is connected by means of a plug-type connection to the mobile gas-measuring device for supplying the mobile gas-measuring device with energy.